Floor cleaning machine

ABSTRACT

Floor cleaning machine comprising: a) a front portion ( 13 ) and a rear portion ( 12 ); the rear portion ( 12 ) comprising at least two lateral rear wheels ( 11 ); b) a chassis ( 10 ) with a lower side ( 22 ) directed towards a floor ( 20 ) to be cleaned and two lateral sides ( 23   a,    23   b ); c) at least one front wheel ( 3 ) arranged in the front portion ( 13 ); and d) a cleaning unit ( 14 ) attached to the chassis ( 10 ) and including at least one rotatable brush ( 6 ) which is arranged in front of the rear wheels ( 11 ) and which has a floor contact region ( 28 ) so as to contact a floor ( 20 ) to be cleaned; wherein the at least one front wheel ( 3 ) is moveable with respect to the chassis ( 10 ) from a retracted position to a lowered position in which it protrudes from the floor contact region ( 28 ) of the at least one brush ( 6 ).

The invention relates to a floor cleaning machine according to the preamble of claim 1.

From DE 692 06 005 BELLATI a planning machine for wooden floors is known, in which—when the machine moves forward—the roller located in front in the forward direction of motion is the lowest roller to exert its action more deeply in the floor and—when the machine moves back—the roller which is located in front in the rearward direction of motion is the lowest roller. This device allows to change the pressure of the rollers on the floor. It is possible to raise a little the rollers during the transfer phase but the driver would have to hold down the handle to this effect which is rather unpractical and burdensome in particular for large and heavy machines.

This known device also discloses a wheel located at the rear of the machine. The wheel can be pivoted about an axis relative to the chassis of the device so that—for stability reasons—the contact point of the wheel is always moved behind the axis. Furthermore, the angle of the axis relative to the floor can be adjusted by means of an actuation knob. By a variation of this angulation of the axis relative to the floor the chassis of the device can be adjusted in such a way that the roller which is arranged in front in the direction of motion is lower than the subsequent roller so as to allow to optimize the functional characteristics with respect to the conditions of the floor to be treated.

EP-A 2 011 426 CRIVELLARO shows a floor cleaning machine with two rear wheels, a steerable front wheel and two auxiliary front wheels which are arranged on mutually opposite lateral sides with respect to the steerable front wheel. The two auxiliary front wheels are used to avoid tipping over the machine when the user climbs in or out of the driver's seat. The steerable front wheel, however, has only a driving function and cannot be adjusted in its height. A disadvantage of this known floor cleaning machine is that the brushes cannot be raised above the floor so that the floor can be damaged due to the brushes which are wetted by cleaning solution.

U.S. Pat. No. 2,749,996 PARKER ET AL. discloses a floor cleansing machine (sweeper) including a main frame carried by two wheels. Furthermore, two driving wheels are attached to the main frame and driven by means of a power unit. This sweeper also discloses a wheel located at the rear of the machine and which can be lifted or lowered vertically by means of the lever. When the rear wheel is moved downwardly to contact the floor the rear frame section together with the driving wheels is raised upwardly, so that the driving wheels are no longer in contact with the floor. However, when the wheel at the rear of the machine is lowered the front of the machine is pushed down and consequently the brushes are compressed. This is disadvantageous because compression of the brushed leads to an undesirable distortion of the bristles of the brushes so that the function of the brushes is impaired.

A further mobile floor cleaning machine is known from U.S. Pat. No. 7,302,734 NOWAK ET AL. This known cleaning machine comprises a hydraulically driven rotating brush, an air mover and a combination of a filter and a receptacle mounted on a chassis with two rear wheels and a front wheel. The steerable front wheel is driven by a hydraulic motor. A disadvantage of this known cleaning machine is that the brush cannot be raised when the cleaning machine is stored or put aside so that tracks or damages on the floor during storage or transport can occur.

Small or medium size floor cleaning machines usually are manually pushed or pulled when moved on the floor, so that a transfer of the machine is cumbersome due to a considerable resistance caused by the brushes slipping on the floor. To avoid this disadvantage the cleaning machine must be tipped by the operator by pressing the handlebar downwardly at the same time as pushing or pulling the machine forward or backward. The effort for tipping the machine can even be increased due to the water sway in the water reservoir, particularly exerted by water in an upper water tank. Furthermore, when the cleaning machine is put aside the brushes can be damaged due to the weight of the machine compressing the brushes. Additionally, the floor can be damaged due to the brushes which are wetted by cleaning solution.

It is an object of the invention to provide a floor cleaning machine that can be more easily moved on the floor when not used and which permits to treat the brushes with care during a transfer of the machine or when put aside and to eliminate tracks or damages on the floor during storage or transport.

The invention solves the posed problem with a floor cleaning machine comprising the features of claim 1.

The advantages of the floor cleaning machine according to the invention can essentially be seen therein that:

-   -   a small or medium size machine can more easily be transferred         over larger distances, e.g. to or from its accommodation;     -   tracks or damages on the floor during storage or transport can         be eliminated;     -   the machine has not to be tipped by pressing the handlebar         downwardly to raise the brush or brushes above the floor when         the machine is transferred or put aside. The operator's effort         for pushing or pulling the machine forward or backward during a         transfer is significantly reduced by eliminating the need of         tipping the machine by pressing the handlebar downwardly at the         same time; and     -   the brush or brushes are more gently treated compared to a two         wheel machine where the brushes are compressed when the machine         is not used and ultimately damaged.

In a special embodiment the front wheel is arranged between the two lateral sides of the chassis, preferably essentially centrically between the two lateral sides. This configuration permits the advantage that the front wheel can be positioned in the free space between the two brushes so that a compact brush unit including the front wheel and its actuator can be achieved.

In a further embodiment the floor cleaning machine comprises at least two front wheels which are laterally arranged and preferably essentially equally spaced relative to a vertical middle plane of the floor cleaning machine. By this means a high stability against canting of the floor cleaning machine can be achieved.

In a further embodiment the floor cleaning machine additionally includes an actuator to move the at least one front wheel from the upper position to the lowered position and vice versa.

In another embodiment the actuator comprises an electric motor, preferably a linear motor to move the at least one front wheel from the upper position to the lowered position and vice versa. Due to this configuration the advantage can be achieved that the brush or brushes can be raised and kept in the raised position without the need of applying—a lot of—manual force so that the adaption of the machine is easy to handle.

In again another embodiment the actuator can be configured as a mechanical actuator, preferably as a threaded spindle to move the at least one front wheel from the upper position to the lowered position and vice versa.

In a further embodiment the at least one front wheel is coupled to a front end of a lever which is pivotably coupled to the chassis and which is rotatable about a pivot axis. This configuration permits the advantage that the linear motor or the mechanical actuator, e.g. a threaded spindle can be arranged with its longitudinal axis extending essentially parallel to the floor so that the height required by the front wheel together with the actuation mechanism can be minimized. Alternatively, the linear motor or the threaded spindle can be arranged with its longitudinal axis extending essentially vertically to the floor.

Preferably, the pivot axis is arranged orthogonal to the middle plane of the chassis.

Preferably, the at least one front wheel is moveable from an upper position, in which the front portion of the chassis is in a lowered position so that the at least one brush is permitted to contact a floor to be cleaned, to a lowered position, in which the front portion of the chassis is in a raised position so that the at least one brush is spaced from a floor to be cleaned. By this means the brush or brushes can be lowered or raised by simply rotating the chassis about the central axes of the rear wheels so that apart from the moveable front wheel no moveable parts are needed in the machine for lowering and raising the brushes.

In another embodiment the cleaning machine comprises more than one, preferably two brushes which are arranged on opposite sides of the middle plane of the chassis and which are rotatable about an axis each, wherein the axes extend on opposite sides of the middle plane of the chassis and transverse to the lower side of the chassis. By this means the cleaning width of the machine can be enlarged without the need of a larger length of the machine.

Preferably, in the lowered position the at least one front wheel vertically protrudes beyond the at least one brush in a direction vertically away from the lower side of the chassis.

Preferably, in the retracted position of the at least one front wheel the at least one brush vertically protrudes beyond the at least one front wheel in a direction vertically away from the lower side of the chassis.

Preferably, the at least one brush is arranged between the at least one front wheel and the rear wheels.

Preferably, the at least one brush comprises a vertical rotational axis. Alternatively, the at least one brush can be arranged with its rotational axis extending in a horizontal direction.

In a further embodiment the at least one front wheel is arranged in front of the vertical rotational axis of the at least one brush.

Preferably, the at least one front wheel is configured as a castor wheel.

In another embodiment the at least one brush—in the lowered position of the at least one front wheel—is vertically raised about minimum 5 mm.

In a further embodiment the cleaning machine further comprises a handlebar which is suitable to move the machine on a floor to be cleaned.

A special embodiment of the invention will be described in the following by way of example and with reference to the accompanying drawings in which:

FIG. 1 illustrates a side view of an embodiment of the floor cleaning machine according to the invention in the working state;

FIG. 2 illustrates a side view of the embodiment of the floor cleaning machine according to the invention of FIG. 1 in a rest state;

FIG. 3 illustrates a top view of the embodiment of the floor cleaning machine according to the invention of FIG. 1;

FIG. 4 illustrates a perspective view of the brush housing including the front wheel of the embodiment of the floor cleaning machine according to the invention of FIG. 1 with the front wheel in the upper position;

FIG. 5 illustrates a perspective view of brush housing including the front wheel of the embodiment of the floor cleaning machine according to the invention of FIG. 1 with the front wheel in the lower position;

FIG. 6 illustrates a perspective view of the brush housing with two front wheels of another embodiment of the floor cleaning machine according to the invention;

FIG. 7 illustrates a side view of the of the brush housing of the embodiment of FIG. 6 of the floor cleaning machine according to the invention wherein the front wheels are in the retracted position; and

FIG. 8 illustrates a side view of the of the brush housing of the embodiment of FIG. 6 of the floor cleaning machine according to the invention wherein the front wheels are in the lowered position.

Although the invention is described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the broad scope of the appended claims.

All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to”. This term encompasses the terms “consisting of” and “consisting essentially of”.

The terms “front”, “rear”, “forward” and “backward” are understood as being directed to a “forward travel direction” of the cleaning apparatus, i.e. a movement of the cleaning apparatus by manually pushing the handlebar towards the front portion of the cleaning apparatus so that the same moves on the floor to be cleaned with the front portion ahead. The term “backward travel direction” is meant to be the opposite travel direction by pulling the handlebar so that the cleaning apparatus moves on the floor with the rear portion ahead. The wording “lateral” or in “a lateral direction” is understood as located beside or extending in a cross direction with respect to the forward and backward travel direction. Furthermore, the terms “lower side of the chassis”, “upper side of the chassis”, “above”, “below”, “vertical” and “horizontal” are referenced to the cleaning apparatus positioned on the floor to be cleaned.

The term “chassis” is understood as being a framework which supports and/or holds in position the various parts of the cleaning apparatus and to which the handlebar is affixed and the rear wheels are rotatably attached.

As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a brush” or “at least one brush” may include a plurality of brushes.

Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging/ranges between” a first indicate number and a second indicate number and “ranging/ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. As used herein the term “method” refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of mechanical engineering.

The word “exemplary” is used herein to mean “serving as an example, instance or illustration”. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.

The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the invention may include a plurality of “optional” features unless such features conflict.

FIGS. 1 to 5 illustrate an embodiment of the floor cleaning machine including a front portion 13, a rear portion 12 with two lateral rear wheels 11, a chassis 10, a front wheel 3, a handlebar 7 and a cleaning unit 14 attached to the chassis 10. The chassis 10 has a lower side 22 directed towards a floor 20 to be cleaned and two lateral sides 23 a, 23 b. The rear portion 12 includes the two lateral rear wheels 11. Exemplarily, the cleaning machine can be provided with a handlebar 6 which is suitable to move the cleaning apparatus 1 on a floor 12 to be cleaned. Alternatively, the cleaning machine can be driven by a motor and controlled by the operator by means of control means attached to the cleaning machine or can be controlled by a remote control. The front wheel 3 is arranged in the front portion 13 essentially centrically with respect to the lateral sides 23 a, 23 b of the chassis 10.

The rear wheels 11 each comprise a central axis, wherein the rear wheels 11 are arranged in such a way that their central axes extend coaxially. The chassis 10 has a middle plane 18 orthogonal to the central axes of the rear wheels 11 and located centrically between the rear wheels 11.

In various embodiments of the cleaning machine according to the invention the cleaning unit 14 can comprise one or more brushes 6. Exemplarily, but not limiting, the embodiments of the cleaning machine illustrated in FIGS. 1 to 8 are provided with a cleaning unit 14 comprising two brushes 6. The brushes 6 are rotatable about a rotational axis each. The brushes 6 can for example, but not limited to, be arranged with their rotational axes extending vertically on opposite sides of the vertical middle plane 18 and essentially vertically to the forward and backward travel direction of the cleaning machine. Alternatively, the one or more brushes 6 can be arranged with their rotational axes extending horizontally in a lateral direction of the cleaning machine. The brushes 6 have a floor contact region 28 so as to contact a floor 20 to be cleaned.

Furthermore, the floor cleaning machine can include an electric power supply 15 to supply electric power to driving motors (not shown) of the brushes 6 and to a vacuum turbine (not shown) allowing to suck the dirty cleaning solution off the floor 20 to be cleaned and into a recovery tank 1. Alternatively, the cleaning machine can be configured without electric driving motors. Apart from the recovery tank 1 the floor cleaning machine includes a clean water tank 9 for the fresh cleaning solution.

Furthermore, the front wheel 3 is moveable from an upper position to a lower position with respect to the chassis 10. When the front wheel 3 is in the upper position the brushes 6 are lowered and contact the floor 20 to be cleaned. Else, when the front wheel 3 is in the lower position the brushes 6 are raised above the floor 20 to be cleaned and spaced therefrom.

The cleaning machine includes an actuator 4 which can be in the form of an electric linear motor 21 to move the front wheel 3 from the upper position to the lower position and vice versa. Alternatively, the actuator 4 can be a mechanical actuator, e.g. a threaded spindle with a central axis arranged in a vertical direction or in a horizontal direction similarly to the direction of the axis of the electric linear motor 21 in FIGS. 4 and 5.

Due to the fact that the brushes 6 can be raised or lowered the machine must only be push or pulled forward or backward by the operator without pressing onto the handlebar 7 to rotate the handlebar 7 horizontally in relation to the floor 20 to be cleaned. During transfer and rest of the cleaning machine (FIG. 2) the front wheel 3 is kept lowered by an electric or mechanically operated actuator 4 which can be actuated by a button 8 located on the handlebar 7.

FIG. 1 illustrates the cleaning machine in working order where the front wheel 3 is kept in the upper position through the action of the electric actuator 4 which can be controlled by an electric button 8 located at the handlebar 7. The handlebar 7 can comprise two handle grips and a control panel with one or more power buttons 8 for the control of the electric actuator 4.

The front wheel 3 is configured as a castor wheel and can swivel about a vertical axis with respect to the floor 20 to be cleaned. In various embodiments the front wheel 3 can have a diameter of minimally about 2 cm and maximally about 30 cm. The front wheel 3 is moveable from an upper position, in which the front portion 13 of the chassis 10 is lowered so that the brushes 6 are lowered and contact the floor 20 to be cleaned, to a lower position, in which the front portion 13 of the chassis 10 is raised so that the brushes 6 are raised so as to be spaced from the floor 20 to be cleaned.

As illustrated in FIGS. 4 and 5 the front wheel 3 is coupled to a front end of a lever 16 which is pivotably coupled to the chassis 10 via a brush housing 5 and a superior support 19. The lever 16 is rotatable about a pivot axis 17 which is arranged orthogonal to the middle plane 18 of the chassis 10. An electric actuator 4 can be coupled with its frond end to the rear end of the lever 16 and with its rear end to the superior support 19 so that the lever 16 can be rotated about the pivot axis 17 by means of the electric actuator 4. With this arrangement, the operator must only push or pull the two handle grips of the handlebar 7 to thereby pushing or pulling the machine horizontally as indicated by arrow 2 in FIGS. 1 and 2 without any additional efforts for tipping the cleaning machine. The sway of dirty cleaning solution inside the recovery tank 1 or of the clean water inside the solution tank 9 is entirely irrelevant for the operator.

FIGS. 6-8 illustrate another embodiment of the floor cleaning machine which differs from the embodiment of FIGS. 1-5 only therein that the floor cleaning machine comprises two front wheels 3 instead of only one. The two front wheels 3 can be configured as castor wheels or alternatively can have fixed axes with respect to the chassis 10. The two front wheels 3 are arranged laterally and essentially equally spaced relative to the middle plane 18. Similarly to the embodiment of FIGS. 1-5 the floor cleaning machine comprises exemplarily, but not limited to, two brushes 6 which are arranged on opposite sides of the middle plane 18 of the chassis 10. Each brush 6 is driven by an electric driving motor 25 attached to the brush housing 5. The front wheels 3 are rotatably kept in wheel frames 24. Each wheel frame 24 is coupled to a shaft 26 which extends orthogonally to the middle plane 18 across the brush housing 5 and which is rotatably attached to the top surface of the brush housing 5. The actuator 4 includes a preferably electrically driven motor 27 suitable to rotate the shaft 26 in either direction to lower or retract the front wheels 3. Alternatively, the actuator 4 can be a mechanical actuator, e.g. a threaded spindle with a central axis arranged in a vertical direction or in a horizontal direction.

Analogously to the embodiment of FIGS. 1-3 the front wheels 3 are moveable from an upper position (FIG. 7), in which the front portion 13 of the chassis 10 is lowered so that the brushes 6 are lowered and contact the floor 20 to be cleaned while the front wheels 3 are spaced from the floor 20 to be cleaned, to a lowered position (FIG. 8), in which the front portion 13 of the chassis 10 is raised so that the brushes 6 are raised so as to be spaced from the floor 20 to be cleaned.

While various descriptions of the present invention are described above, it should be understood that the various features can be used singly or in any combination thereof. The scope of the present invention is accordingly defined as set forth in the appended claims. 

1: A floor cleaning machine comprising: a front portion; a rear portion comprising at least two lateral rear wheels; a chassis with a lower side directed towards a floor to be cleaned; two lateral sides; at least one front wheel arranged in the front portion; and a cleaning unit attached to the chassis and including at least one rotatable brush, which is arranged in front of the rear wheels and which has a floor contact region so as to contact the floor to be cleaned; wherein: the at least one front wheel is moveable with respect to the chassis from a retracted position to a lowered position in which it protrudes from the floor contact region of the at least one brush; and the floor cleaning machine further includes an actuator comprising an electric motor to move the at least one front wheel between the retracted position and the lowered position. 2: The floor cleaning machine according to claim 1, wherein the front wheel is arranged between the two lateral sides of the chassis. 3: The floor cleaning machine according to claim 1, wherein the floor cleaning machine comprises at least two front wheels, which are laterally arranged. 4: The floor cleaning machine according to claim 1, wherein the actuator is controllable by an electric button located at a handlebar of the floor cleaning machine. 5: The floor cleaning machine according to claim 1, wherein the actuator comprises a linear motor to move the at least one front wheel between the retracted position and the lowered position. 6: The floor cleaning machine according to claim 1, wherein the actuator is configured as a mechanical actuator. 7: The floor cleaning machine according to claim 1, wherein the at least one front wheel is coupled to a front end of a lever, which is pivotably coupled to the chassis and which is rotatable about a pivot axis. 8: The floor cleaning machine according to claim 7, wherein the pivot axis is arranged orthogonal to a middle plane of the floor cleaning machine. 9: The floor cleaning machine according to claim 1, wherein when the at least one front wheel in the retracted position, the front portion of the chassis is in a lowered position so that the at least one brush contacts the floor to be cleaned, and wherein when the at least one front wheel is in the lowered position, the front portion of the chassis is in a raised position so that the at least one brush is spaced from the floor to be cleaned. 10: The floor cleaning machine according to claim 1, wherein the floor cleaning machine comprises at least two brushes, which are arranged on opposite sides of a middle plane of the floor cleaning machine and each of which is rotatable about an axis, wherein the axes extend on opposite sides of the middle plane of the floor cleaning machine and transverse to the lower side of the chassis. 11: The floor cleaning machine according to claim 1, wherein in the lowered position the at least one front wheel vertically protrudes beyond the at least one brush in a direction vertically away from the lower side of the chassis. 12: The floor cleaning machine according to claim 1, wherein in the retracted position the at least one brush vertically protrudes beyond the at least one front wheel in a direction vertically away from the lower side of the chassis. 13: The floor cleaning machine according to claim 1, wherein the at least one brush is arranged between the at least one front wheel and the rear wheels. 14: The floor cleaning machine according to claim 1, wherein the at least one brush comprises a vertical rotational axis. 15: The floor cleaning machine according to claim 14, wherein the at least one front wheel is arranged in front of the vertical rotational axis of the at least one brush. 16: The floor cleaning machine according to claim 1, wherein the at least one front wheel is configured as a castor wheel. 17: The floor cleaning machine according to claim 1, wherein in the lowered position of the at least one front wheel the at least one brush is vertically raised a minimum of about 5 mm. 18: The floor cleaning machine according to claim 1, wherein the cleaning machine further comprises a handlebar for moving the floor cleaning machine on the floor to be cleaned. 19: The floor cleaning machine according to claim 2, wherein the front wheel is arranged essentially centrically between the two lateral sides of the chassis. 20: The floor cleaning machine according to claim 3, wherein the at least two front wheels are laterally arranged essentially equally spaced relative to a vertical middle plane of the floor cleaning machine. 21: The floor cleaning machine according to claim 6, wherein the actuator is a threaded spindle configured to move the at least one front wheel between the retracted position and the lowered position. 22: The floor cleaning machine according to claim 10, wherein the floor cleaning machine includes only two brushes 